Home Assistant shifts into high gear with Matter 1.6.1 and matter.js

Matter is moving fast, and this time it directly affects Home Assistant users. matter.js, the library that has powered Home Assistant’s new Matter Server for the past few months, now supports the new features in Matter 1.6.1.

The version number may not look like much, but there’s plenty in it: group communications with Groupcast, better handling of battery-powered devices, additional controls for OTA updates, and a few sensor improvements.

The most important change lies elsewhere. By replacing its old Matter server, built on the C++ SDK, with matter.js, Home Assistant has put itself in a position to keep up with the standard much faster. And that’s starting to show.

Home Assistant has changed its Matter engine

Home Assistant has supported Matter since the standard’s early days. Until recently, its Matter Server was written in Python and relied on the official C++ SDK. It worked, but it came with some limitations.

In June 2026, the Open Home Foundation released Matter Server 9.0, completely rewritten using matter.js. matter.js is an open-source implementation of Matter in TypeScript, now hosted by the foundation. Home Assistant isn’t the only one using it, either: Homebridge and openHAB use it too.

From the user’s perspective, the migration happens almost entirely on its own. Matter Server 9.0 replaces the old server and imports its data on first startup. Home Assistant still recommends making a backup beforehand.

The improvements were immediately noticeable: much faster restarts, optimized device reconnections, better performance on busy Thread networks, and partial device queries instead of rereading everything each time.

Most importantly, this new foundation makes adopting subsequent versions of Matter much easier.

Matter 1.6 was already here

Matter 1.6.1 isn’t starting from scratch: Home Assistant’s Matter Server had already moved to Matter 1.6.0, notably with version 9.1.

This version added time synchronization with compatible devices and experimental support for energy-saving features for ICDs (Intermittently Connected Devices).

These ICDs are important for what comes next. A light bulb plugged into mains power can stay connected all the time without worrying about its power consumption. A contact sensor, button, or remote that needs to last for years on a coin-cell battery can’t. It needs to sleep most of the time, wake up when it has something to report, transmit quickly, and go back to sleep.

matter.js now handles these devices in detail, both on the server and controller sides: registering ICD clients, handling wake-ups, and tracking their availability.

In home automation, that matters a lot. Many of the sensors we install at home need to last for years without us having to change their batteries every few months.

With Matter 1.6.1, it’s time for Groupcast

Of the Matter 1.6.1 features integrated into matter.js, the one I’m most interested in is Groupcast.

Usually, a controller communicates with each device separately. To turn off ten light bulbs, it sends a command to each one.

Groupcast adds multicast group sessions: a single command can target all the devices in the same group. matter.js now enables the Groupcast cluster and everything needed to manage it.

Imagine a Matter group with all the light bulbs in the living room. “Turn off the living room” is sent to the group, not to each bulb one after another.

With three devices, you won’t notice the difference. With several dozen Matter devices in the house, you will.

Zigbee users will recognize the idea of groups: the network handles some of the work instead of leaving everything to the controller.

That said, just because matter.js can do it doesn’t mean you’ll be able to create groups from the Home Assistant interface tomorrow. The Matter Server, and then Home Assistant, still need to make use of these features. But the groundwork is in place.

Better handling for battery-powered devices

The other major area of work is ICDs.

matter.js supports the IcdManagement cluster on the server side: registering and removing clients, StayActiveRequest requests, SIT and LIT modes, and the mechanisms that let a sleeping device signal that it has woken up.

On the controller side, registration can be automated, and matter.js tracks the state of devices that spend most of their time asleep.

Put that way, it sounds very technical.

In practical terms, imagine a Matter over Thread contact sensor running on a battery. If it sleeps for several minutes to save battery, the controller shouldn’t assume it’s disconnected. It needs to know how it works and when it’s expected to check in.

The user never sees this kind of detail. Yet it’s what separates a pleasant technology from a sensor that shows as “unavailable” three times a day.

OTA updates are improving too

matter.js can now retrieve compliance information associated with a software version from Matter’s Distributed Compliance Ledger (DCL). This information can be used when checking for OTA updates.

The DCL is relatively obscure. It’s a distributed registry maintained by the Connectivity Standards Alliance, which publishes information about certified devices, including metadata useful for distributing firmware.

Home Assistant already creates an update entity for Matter devices that support OTA, and checks the DCL every twelve hours by default. Not all manufacturers are on board yet, but Home Assistant cites Eve and Nanoleaf among those that use this mechanism.

The idea is to eventually keep your Matter devices up to date from your home automation controller, without installing the manufacturer’s app just to update the firmware on a sensor or plug.

There are still limitations. For example, Home Assistant notes that OTA updates are currently problematic for Thread devices when the network uses Apple Border Routers: some mDNS packets, which are needed to find the update provider, aren’t relayed.

In short, progress is being made, but it’s not magic yet!

Matter 1.6 makes device setup easier

It’s also worth putting Matter 1.6.1 in the context of what Matter 1.6, published by the Connectivity Standards Alliance, brought to the table.

This time, the CSA didn’t set out to add a slew of product categories. Instead, it focused on setup, coexistence between ecosystems, and communication between devices.

The feature that surprised me most: bidirectional NFC commissioning. With Matter 1.4.1, it was already possible to transfer setup information over NFC, but the rest still had to happen over Bluetooth LE. With Matter 1.6, the entire commissioning exchange can take place over NFC.

In theory, you can set up a Matter wall switch before even powering it on, simply by bringing your smartphone close to it.

For a homeowner, that’s convenient. For an electrician setting up several dozen devices before installing them in a home, the time savings are significant.

Joint Fabric for multi-ecosystem homes

Matter 1.6 also introduces Joint Fabric, designed for setups where multiple home automation systems coexist.

A Matter device can already belong to multiple Fabrics, meaning multiple Matter logical networks. This is what allows it to be shared between multiple ecosystems.

Joint Fabric takes a different approach to the problem: multiple authorized controllers administer one shared Fabric, and devices added to it become accessible to all participating controllers.

You can immediately see the benefit in a home running Home Assistant where some family members still use Apple Home or Google Home.

It’s even more relevant in commercial buildings, rentals, or new homes, where several parties may need to administer a setup for a time.

Devices provide more information about their status

Matter 1.6 also brings less flashy improvements on paper that could prove useful in Home Assistant.

Devices describe more precisely what they can do and their operating limits. Security sensors can transmit the history of certain events. Smoke and carbon monoxide detectors can even report that they’ve been removed from their mounting location.

This is the kind of information you can use in automations. A smoke detector removed from its mount can trigger a notification. A security sensor’s history can be displayed on the dashboard. And if Home Assistant knows more about a device’s capabilities, it can tailor the features it offers.

That all depends on manufacturers implementing these features and then Home Assistant exposing them. A new version of the spec won’t magically update the millions of devices already installed.

A Matter network map in Home Assistant

The new matter.js server also brought a very useful feature: a map of the Matter network.

Home Assistant displays Matter devices and how they connect to the controller. On Thread, you can distinguish routers, end devices, and sleeping devices, as well as the hops communications take. Link quality is visible too. For Wi-Fi, Home Assistant shows the access point in use and the connection quality.

That’s invaluable when a Thread network is acting up.

According to the current Home Assistant documentation, you need Matter Server 9.2.0 or later. The map is under Settings > Connectivity > Matter > Show Map.

It’s a far cry from the black box of the integration’s early versions!

Matter 1.6.1 doesn’t mean all of this will be in Home Assistant tomorrow

A quick clarification, though.

The Connectivity Standards Alliance officially publishes the Matter 1.6.1 specifications, and matter.js already incorporates several changes from this version. But there are several steps between a feature being written into the standard and a button appearing in Home Assistant. The feature has to be defined by Matter, implemented in matter.js, used by the Matter Server, exposed by the Home Assistant integration, and, of course, supported by the device itself.

The official Matter Server repository still lists support for Matter 1.6.0.

So it would be premature to say that Home Assistant “fully supports Matter 1.6.1.” However, the necessary building blocks are already in matter.js, and that’s what I think is worth taking away.

matter.js, one of Home Assistant’s best decisions?

For a long time, Matter seemed to be progressing faster on paper than in our homes. Every new spec promised great things, then we had to wait for manufacturers, controllers, and ecosystems to catch up.

The move to matter.js changes things a little. The Open Home Foundation now controls a central part of its Matter stack. And because matter.js is an open-source project hosted by the foundation itself, new features in the standard make it to the Matter Server much faster.

This is no longer a niche topic: when it announced the new server in June 2026, Home Assistant said Matter was used in 38% of installations, making it the twelfth most-used integration.

Matter 1.6.1 probably won’t make ten new buttons appear on your dashboard tomorrow morning. But with Groupcast, finer-grained handling of sleeping devices, OTA improvements, and everything Matter 1.6 brings, the foundation is getting solid.

And Home Assistant finally seems capable of keeping up with future Matter versions instead of remaining several steps behind.

For those of us who, like me, experienced the early growing pains of Matter and Thread, this may be the best news of all!